Hempcrete R Value

Hang on, what actually is an r-value?

It’s simply a unit of measurement to show thermal conductivity of a material.

The higher the R-Value, the better the insulation.

Think of it like a jumper, one made from cotton and one made from merino will perform completely differently.

Whether you’re building your dream home or retrofitting an existing structure, pay close attention to the R-values of the materials you’re using. Its a real game changer

It’s one of the main reasons why Hempcrete, a natural building material, is fast becoming the go-to for architects, builders, and green-conscious homeowners looking for the perfect balance of thermal performance, sustainability, and health. Want to know what truly makes Hempcrete stand out and how well it really insulates? We’ve got you covered.  

Is all Hempcrete the same?

Hempcrete is a bio-composite building material made from the woody core of the hemp plant (called hemp shiv), mixed with a natural lime binder and water. Once set, it forms a breathable, lightweight, and insulating material that’s perfect for internal and external walls. Because Hempcrete is not load-bearing on its own, it’s used in conjunction with a structural frame. Nonetheless, its benefits are nothing short of exceptional.

But let’s be real: not all Hempcrete is created equal. As a leading Hempcrete supplier in Australia, what sets Respirabuilt apart is the unmatched care and craftsmanship that goes into every block. Here’s what makes Respirabuilt the go-to choice for Hempcrete insulation in Australia:

Sustainability

• 100% natural and cement-free

• Made from sustainably sourced hemp

• Carbon-negative material, absorbing more CO₂ than it emits

Health & Safety

• Contains zero harmful chemicals

• Creates toxin-free living spaces

• Naturally mould-resistant

• Deters pests without needing synthetic treatments

Performance

• Superior fire resistance

• Excellent acoustic insulation

• Outstanding thermal insulation, reducing the need for artificial heating and cooling

Material Quality

• Made using high-grade hemp shivs and premium lime binders

• Durable, breathable, and resilient

• Maintains its structural integrity over decades

Ease of Use

• Lightweight and simple to install

• Speeds up the construction process and cuts down on labour costs

Trust & Assurance

• Guaranteed consistency and high-quality manufacturing

• Transparent sourcing and production practices

Ideal For

• Green building projects focused on sustainability and performance

• Eco-conscious Australian homes aiming for long-term energy efficiency

With RespiraBuilt, Hempcrete isn’t just another building material. It’s the ultimate foundation for a better, healthier, and more energy-efficient future.

What is the R Value of Hempcrete?

So how does Hempcrete perform when it comes to R-value? Remarkably well, actually. 

The Hempcrete R-value depends largely on the thickness and the type of blocks used. Respirabuilt blocks for example, offer an average of 40% higher R value compared to standard Hempcrete blocks. They range in sizes to suit various insulation needs, and all deliver unmatched thermal performance for the price. Here’s a quick look at the options available:

These figures highlight just how effective Hempcrete can be. The Hempcrete R-value of the RB300, for instance, far outperforms essentially all competing building materials and helps homeowners lock in long-term energy savings.

It’s also worth noting that, unlike synthetic insulation materials, Hempcretes properties are fundamentally different

Lets have a look:

Synthetic Insulation
Very, very slow to dry when wet
Loses its insulation value once damp
Moisture gets trapped and lingers
Sags, slumps, and breaks
down over time
Natural Insulation
Dries out quick, even after absorbing moisture (hemp wicks it away)
Still insulates with moisture present
Breathes — takes in and releases moisture freely
Holds shape, stays solid, and lasts for decades
Brilliant for the planet & your lungs

Wondering how much it costs to build with Hempcrete? Check out our Hempcrete block cost calculator. 

Making the Right Choice for Your Build

When selecting insulation materials for your home or project, it’s easy to get lost in numbers. But with Hempcrete, you get more than just thermal performance. You get a building envelope that works with nature, not against it. It’s the key to creating a space that’s warm, quiet, safe, and sustainable. Plus, Hempcrete’s fire resistance makes it ideal for building in bushfire-prone regions. That’s an increasingly important consideration to put on your radar.

RespiraBuilt Hempcrete blocks provide an ideal blend of modern performance and environmental responsibility. Ultimately, you’re not just insulating your home; you’re investing in your wellbeing and the future of the planet.

Thanks to the wide range of R-values available, it’s easy to find a block that suits your needs and budget. Whether you’re after the ultra-efficient RB300 or the affordable RB80, there’s a Hempcrete option ready to take your build to the next level of innovation. 

Start Building Smarter with Respirabuilt 

Hempcrete is more than just a green building trend that’s bound to fade over time. It’s a high-performance insulation solution designed for the future of Australian homes. 

With exceptional R-values, unmatched sustainability, and superior health and safety benefits, Hempcrete by Respirabuilt delivers everything you need for a comfortable and conscious home. Whether you’re building from scratch or retrofitting, explore premium Hempcrete blocks that combine performance, peace of mind, and planet-friendly living.

Looking for more expert insights beyond Hempcrete R values? Take a look at our other helpful resources below: 

• How Does Hempcrete Compare to Traditional Insulation Materials?

• Sustainable Building Materials Australia

• Hempcrete disadvantages